Estimates of heritability and genetic covariance can be biased if the underlying model of genetic architecture is misspecified, e.g., if variance explained is correlated with LD Score or MAF [19, 21]. Because genetic correlation is estimated as a ratio, it is more robust; biases that affect the numerator and the denominator in the same direction tend to cancel. We obtain approximately correct estimates of genetic correlation even in simulations with models of genetic architecture where our estimates of heritability and genetic covariance are biased (Supplementary Table 2).
